


A Trick and a Treat

by jadztone



Category: Sherlock (TV)
Genre: Alternate Universe - High School, Don't copy to another site, First Kiss, Fluff, Halloween, Kidlock, M/M, Teen!Mystrade, Trick or Treating
Language: English
Status: Completed
Published: 2019-10-20
Updated: 2019-10-20
Packaged: 2020-12-24 11:08:29
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,258
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21098480
Author URL: https://archiveofourown.org/users/jadztone/pseuds/jadztone
Summary: It's Halloween and teen!Mycroft is escorting his little brother from house to house, when Sherlock tricks him into coming face to face with his crush, Greg. Much to Mycroft's surprise, Greg acts like he's the one who's been given a treat.





	A Trick and a Treat

**Author's Note:**

> From the moment I saw this fan art, I knew I wanted to write a fic about it some day. And that day has come: [cute fan art](https://iraya.tumblr.com/post/100381236709)
> 
> For the location, I did some googling and Dulwich village seemed to fit the bill for the type of atmosphere I wanted while still being located in London. The outdoor viewing of The Conjuring thing I stumbled across with more googling, and decided to incorporate it.
> 
> Much thanks to ReynardinePttr for britpicking this for me!

“Mycroft! If you don’t stop looking at your mobile, you’re going to be run over!” Mycroft stopped walking and glanced up to see Sherlock giving him an admonishing look. He felt his face grow warm when he realised that his little brother was right. He’d been about to step out into the street without realising it. And _he_ was supposed to be the one watching out for _Sherlock_. Mycroft hastily shoved his mobile in his back pocket and looked both ways before they crossed the street.

Dulwich was swarming with children as they darted from home to home, eager to fill their bags with treats. Sherlock had initially declared the idea dull; not even his friend John could convince him it would be fun. Mycroft suspected that he didn’t like the idea of wearing a costume, believing at the ripe old age of 10 that he would look foolish. 

Careful not to make it a suggestion (as that would have been _immediately_ disregarded), Mycroft slyly implied that Sherlock could dress like a pirate. Sherlock was entirely enamoured of pirate lore, and to him pirates were anything but foolish. Therefore, _logically_, he would not look foolish if he dressed as one.

In retrospect, Mycroft heartily regretted aiding and abetting their parents. His success in getting Sherlock to agree to the outing led to them putting Mycroft in charge of chaperoning him. Their argument being that it wasn’t as if Mycroft had any other plans. He most certainly did have plans – he was doing research for his history essay on why Napoleon _really_ lost at Waterloo – but he knew his parents would declare it did not count. Mycroft knew what they were up to. They wanted both of their boys to participate in societal norms, and hoped to kill two birds with one frivolous holiday. They believed that Mycroft would be more likely to actually go to a party if the alternative was to ferry Sherlock around. What they didn’t understand was that Mycroft tolerated Sherlock far more than any of his own peers.

Well, not _all_ of his peers. Mycroft found one or two people somewhat tolerable. And then there was Greg Lestrade. Mycroft might even say that he found Greg to be a most…agreeable sort. Unlike most of his classmates, Greg never looked at him as if he were some sort of alien. He was always smiling at him, though Mycroft never read anything into it. Greg smiled at everyone, it was purely reflexive for someone so outgoing and cheerful. It didn’t even matter that Greg surely hadn’t noticed the recipient of his smile - it still pleased Mycroft enormously to have one bestowed on him. There was also the fact that Greg was gorgeous, and fit, and yet not at all full of himself.

Mycroft found himself wondering if he might have been tempted to attend a Halloween party if he knew Greg was going to be there. This was purely hypothetical, as Mycroft would have to have been invited to such an event. But _hypothetically_…it might have been nice to see him in a social setting. Or terrible. If he were being honest with himself, he would use every ounce of courage getting himself to the party and then spend the rest of it hiding in a corner staring wistfully at the object of his affection. Better that he was out here with his brother, contenting himself with the images Greg was posting on Snapchat.

It was hard to tell where Greg was based on the photos. They’d all been selfies – Greg in a frankly hideous jumper adorned with carved pumpkins, Greg posing with a skeleton decoration, Greg eating sweets, Greg’s gorgeous face obscured by a purple monster mask. No one else in the pictures so far. No sign of party goers. No indication of a _date_.

Mycroft didn’t know why he tortured himself every weekend looking for any signs on Greg’s social media that he was dating someone. From what Mycroft heard, he used to have a girlfriend, but they broke up a year ago when she cheated on him. Greg has been on a handful of dates since – both boys and girls – but no one serious. Why did it matter if he did become serious with someone? It wasn’t like Mycroft would be missing his chance if Greg were taken off the market. He had no chance at all, no matter what Greg’s status. Having said that, sometimes he wished Greg _were_ serious about someone. Because as much as Mycroft told himself he didn’t have a chance, there was that stupid part of him that daydreamed what ifs. 

Mycroft felt his mobile buzz and saw that Greg had updated his snapchat. This one was a video – a door opening to reveal several children dressed up as various Doctor Who characters. Greg was saying something in a delighted tone, but it was difficult to hear with the background noise of the street. Did this mean…was Greg at home giving sweets to trick-or-treaters?

“Mycroft!!” He jerked his head up to see Sherlock glaring at him again. “Watch where you’re going or you’ll trip over the steps!” A ridiculous warning, as Mycroft had already stopped just shy of them. Sherlock waved his hand irritably, motioning for him to follow him to the door. Why did Sherlock want him to go up with him? At the last few houses, he’d insisted on Mycroft standing as far away as possible. 

Sherlock rang the doorbell, and the door opened to reveal someone wearing…Mycroft’s mouth went dry…a purple mask and a pumpkin-patterned jumper. The figure made a growling noise, followed quickly by a giggle as Sherlock rolled his eyes and said in a bored voice, “Trick or treat.”

The person pushed his mask up onto his forehead, revealing…as Mycroft had suspected…Greg Lestrade. Mycroft felt a little faint. He’d been paying so little attention to their surroundings that he’d had no idea they were approaching the house of his crush. If only Sherlock hadn’t made him come up to the door. It was almost as if he had _known_. Mycroft glanced over at his brother, his gaze suspicious. Sherlock had a smirk on his face.

“Mycroft?” His eyes darted back to Greg’s, who was regarding him with a pleased grin. Mycroft blinked rapidly. Greg knew his name? He opened his mouth to reply, but was unable to come up with any sort of rational reply. Greg’s brow wrinkled. “Are you okay?” 

Mycroft still couldn’t think of anything to say, just continued to stare at Greg, who was staring back at him as he absentmindedly shoved treats into Sherlock’s bag. A couple of pieces missed the bag and fell to the ground. This was apparently too much for Sherlock, who exclaimed, “Watch it, you idiot, that’s a waste of perfectly good sweets! And he’s fine, he’s just embarrassed to be seen out with his little brother by the most popular boy in school.”

Mycroft’s face had started to grow hot at his brother’s rudeness, but now it felt like flames were engulfing him. Greg just grinned down at Sherlock as if he thought being called an idiot by a 10 year old was adorable. He looked back at Mycroft, his smile softening. “I don’t know why you would be embarrassed. I was planning to take my sister out, but she said she was too old for trick-or-treating. A bit disappointed, if I’m honest.”

Sherlock shook his head. “_Nnnnope_! She’s out trick-or-treating right now, she just didn’t want to be seen with you looking like that.” He gestured towards Greg’s jumper.

Mycroft felt like murdering his sibling, but Greg doubled over in laughter. “Oh my god, your brother is a riot!” 

Mycroft wrinkled his nose. “If you find him so charming, you should come with us and see what he’s really like. You’ll weary of his sharp tongue soon enough.”

Greg’s smile widened. “You really want me to join you?” 

Mycroft stared at him in horror. That was not what he meant at all! He opened his mouth to assure Greg that he would _never_ suggest he’d actually want to spend time in his company, but Sherlock spoke first. “If you’re going to come along, hurry up! Mrs. Hudson’s house is next and she always gives out full size chocolate bars. If we don’t get a move on, they’ll all be taken!”

Greg laughed, “All right, then! Hold on.” He stepped back into the house and called out to his mum that she was now on door duty, then came outside and shut the door behind him. “Lead the way, Pirate King!”

Mycroft was in a daze, not able to comprehend how all this came about. He followed the other two as they started down the street. Sherlock turned back and said, “Now that he’s actually here in person, maybe you’ll stop looking at his snapchat and pay attention.”

Mycroft keenly felt the urge to run in the other direction. Greg’s eyes gleamed as he regarded him. “Yeah, Mycroft, pay attention. Then maybe you’ll see what’s right in front of you.” Mycroft wasn’t sure what to make of that, so he stayed silent as they approached Mrs. Hudson’s house. 

While Sherlock went to the door and endured Mrs. Hudson’s cooing, Greg took out his mobile and opened his snapchat. Without warning, he slung his arm around Mycroft and took a selfie of the two of them. Mycroft felt all the air leave his lungs as he watched Greg type out his caption. Mycroft felt his mobile vibrate, knowing it was the snapchat alert. Greg was looking at him with a smirk, so the last thing Mycroft wanted to do was check. But curiosity got the better of him. He winced at the gobsmacked look on his face in the picture, but then his jaw dropped when he read the caption. “Finally got posh boy to notice me, all it took was this ugly jumper.”

Mycroft lifted his gaze in astonishment. “Of course I noticed you before tonight! As Sherlock so…so _mortifyingly_ pointed out, I follow you on social media. What I don’t understand is…you _wanted_ me to notice you? Me?”

Greg raises his eyebrows. “Of course! I’ve been trying to get your attention for ages. Always saying hi to you, letting you borrow my pencil, that time I ran over to pick up your books when you dropped them.”

Mycroft blinked. “I thought you were just being nice.”

“I was _trying_ to strike up a conversation, but you always bolted. I figured maybe I wasn’t your type. Maybe you don’t go for athletes or something.”

Mycroft bit his lip. “Well…I never thought that I did. Until you. Sports don’t really appeal to me. But you…play very well.”

Greg’s smile turns sultry. “You’ve been to my rugby matches?”

Before Mycroft could admit that he had, Sherlock came up and inserted himself between them with an irritated expression. “I should have deduced that bringing him along would make it worse, not better. I always miss something!” Mycroft was bracing himself as it appeared Sherlock was about to embarrass him some more. But his brother stopped short when he saw something ahead of them. “John! John Watson!” He darted forward.

Mycroft spotted his brother’s friend coming their way, Harry trailing behind him with a bored look on her face. John sped up when he saw Sherlock. Mycroft wasn’t exactly sure what John was supposed to be. He had on a white shirt with a black waistcoat, dark blue trousers with stripes up the side, and black boots.

Mycroft glanced over at Greg, and was startled to see that he was looking at Harry with a speculative gleam in his eyes. Mycroft had a queasy feeling of jealousy when Greg called out, “Oi, Harry!” and started walking quickly towards her. Mycroft trailed after him in confusion. Greg obviously knew her, so didn’t he also know she’s a lesbian?

Harry smirked at Greg as he approached. “Hey there, Greggles.”

Greg nodded at the two boys, who were now giggling as they compared their loot so far. “I didn’t know John was thick with Mycroft’s little brother.” 

Harry rolls her eyes. “Are you kidding? When these two get together, you couldn’t separate them with a grenade. Hey, Myc.” Mycroft winced at the nickname, but gave her a polite nod.

Greg gave Mycroft a sly look, then turned back to Harry and cleared his throat. “Yeah, so I can tell. Especially not on a night like tonight, I can already see them plotting which house to hit next. Seems a waste of time for all three of us to chaperone them.” Mycroft’s heart sank, wondering if Greg had decided she would be better company and he was planning to take off with her and leave Mycroft with the boys. 

Harry gave Greg a knowing look. “I know what you’re after, Greg Lestrade, don’t think I can be fooled by a pair of pretty brown eyes. You want _me_ to look after both of them so you can find some dark and spooky corner to have this one to yourself.” She leered at Mycroft and his face went brick red. 

Greg rolled his eyes. “Christ Harry, why you always gotta be so crass? I dunno what Clara sees in you.”

Harry snorted. “I don’t either, I know I’m pretty damn lucky. And since you were the one who introduced us, I suppose I owe you one. Get out of here before I change my mind.”

Greg’s face lit up like the pumpkins on his jumper. “You’re the best, Harry!” He kissed her on the cheek.

She made a face and said “Ugh, boys.”

Greg turned to Mycroft and held out his hand. “Let’s get out of here.”

Mycroft shyly put his hand in Greg’s, feeling goosebumps race up his arm. “W-where do you want to go?”

“They’re playing The Conjuring at Belair House. It’s outdoors, so I’ll have to stop back home to get snacks and a blanket that will fit around both of us.” He bit his lip, suddenly looking a bit shy. “I mean, if that’s alright.”

Mycroft gazed at this beautiful boy in disbelief. He actually thought Mycroft might refuse? “It sounds perfect, Greg.”

Mycroft went over to let Sherlock know he was leaving. John was explaining to him that he was Han Solo, a space smuggler, which was a lot like a pirate. Sherlock was nodding and grinning. Mycroft told Sherlock to behave, not really confident his brother heard a word of it. 

They set off back towards Greg’s home. They’d only gone a few steps when Greg called out, “Oi! I see you, Becks!” Mycroft spotted Greg’s little sister, surrounded by other 13 year olds, all dressed like…if he had to take a guess… zombies. She cringed when she saw him. “Thought you were too old for trick-or-treating?”

She folded her arms and huffed. “I’m too old to be trick-or-treating with a chaperone. Anyway, it worked out well for you, didn’t it?” She gave a significant look to his hand in Mycroft’s. 

Greg grinned. “It sure did, and that’s the only reason I’m gonna let this pass. That is, _if_ you get home by curfew. Otherwise I have ways of making you pay. Very, very embarrassing ways.”

His sister rolled her eyes, gave him a fake smile, then strolled off in the opposite direction. Greg turned to Mycroft and raised his eyebrows. “Christ, I hope that worked. If she gets into trouble, my skull will be the first one mum cracks. Come on.” He tugged at Mycroft’s hand, and he followed along willingly.

They stopped at Greg’s house for the needed supplies, and to tell his mother where they were going. Mycroft updated his own parents via text. Rather than be annoyed that he fobbed Sherlock off on someone else, his mother’s gushing reply confirmed what he’d thought earlier – they were eager for him to socialise with his age group. His mother needn’t know that there was only one other person he was with, and they wouldn’t exactly be ‘socialising.’

As they made their way up to where the movie was showing, Mycroft’s nerves started to get the better of him. He was a bit relieved that they would be seeing a movie, as it would ease the pressure to keep Greg entertained. He was still bewildered why someone as wonderful as Greg would be interested in him. Had been interested for some time, apparently. It boggled the mind to think his crush was reciprocated. So much time wasted, because Mycroft had been too stupid to pick up on the social cues. What else would he get wrong?

“You’re being awfully quiet over there.” Mycroft blinked, turning his head to look at Greg. 

“Oh! I’m just…still a bit…” Mycroft decided to go for full honesty. That way if Greg was put off, it would be before he got too attached. “Greg, I don’t do this sort of thing.”

Greg’s brow wrinkled. “Go to horror movies?”

“Go on dates…if that’s what this is.”

Greg stopped, his expression troubled, letting go of his hand. Mycroft braced himself. “D’you not want this to be a date? We can go as just friends. Though I wish you’d told me before, I’d have grabbed another blanket. It’ll be a bit awkward cuddling if you’re just wanting a friend.” He unsuccessfully tried not to look disappointed.

Mycroft melted at Greg’s willingness to respect his perceived boundaries. “Oh! N-no, that’s not what I meant. I-I do want this to be a date, I’ve just…never been on one before. I don’t know what I’m doing, in case you haven’t noticed.”

Greg looked relieved, and stepped closer, taking his hand again. He leaned over and whispered in Mycroft’s ear. “As long as you want to be with me, I don’t really care about all that. All you need to do is let me know if I go too fast for you, alright?” Mycroft’s lips curved in a shy smile, and he nodded.

They continued on, and when they had arrived and paid for their tickets, Greg found a spot on the grass and spread out a thick blanket. He sat and pulled Mycroft down next to them, then draped the larger blanket around them. “Warm enough?” Mycroft nodded, but then shivered a little. Greg chuckled and put his arm around Mycroft underneath the blanket.

Mycroft’s shiver hadn’t been from the cold. Greg’s face was _close_. So close that the slightest tilt of his head could lead to them kissing. He wanted very much to try it, but he worried that he would be the one going too fast for Greg. “Mycroft?”

Mycroft looked up from his musings, their eyes locking. “Hmm?” It almost came out a squeak.

“If you’ve never dated before, does that mean you’ve never been kissed?”

Mycroft blushed. “Technically, I was kissed at age 9 by a girl in my class. I don’t really count it since it wasn’t a boy and wasn’t consensual.”

Greg chuckled. “Do you want to be kissed by a boy? Consensually?” 

The way he said consensually, with the emphasis on sensual, made Mycroft shiver. He nodded. “It would be entirely consensual if the boy were _you_.”

Greg grinned, and then tilted his head. Just as Mycroft thought, that was all it took for their lips to meet. That was the last rational thought he had, as he melted into Greg’s lips and his arms. 

**Author's Note:**

> I hope you enjoyed this. You can find me gushing about these lovely characters on sherlock-nanowrimo.tumblr.com


End file.
